Indicia have been applied to curved surfaces in manners known in the art. For example, paint has been applied to car fenders, labels have been applied to cylindrical containers and instructions have been printed on or molded into camera bodies, as is known in the art.
Much of the art has been concerned with flat surfaces, such as flexible webs, including woven and nonwoven materials, and rigid surfaces, such as cardboard boxes or plastic as may be used for credit cards. Other art is concerned with surfaces curved in a single plane, such as a cylindrical container. Indicia may be applied to cylindrical containers using adhesive attachment, as may occur with a small prescription bottle or using a heat transfer label as may occur with a large bottle.
However, little attention has been paid to applying indicia to a compound curved surface. By compound curved, it is meant that the surface has curvature about two or more different axes. For example a barrel-shaped container has round (and closed) curvature about the longitudinal axis and convex (and open) curvature about a radial line perpendicular to the longitudinal axis. An hourglass-shaped container also has round (and closed) curvature about the longitudinal axis and concave (and open) curvature about a radial line perpendicular to the longitudinal axis. A sphere and a football have closed compound curvature about two orthogonal axes.
By closed it is meant that the periphery of the curvature forms a closed figure such as a circle, oval, ellipse, an irregular circumference subtending 360 degrees, etc. By open it is meant that the surface has two ends mutually spaced apart, as may occur with the top/bottom of a barrel or hourglass.
One attempt in the art to apply indicia to a curved surface is shown in U.S. Pat. No. 5,117,993. An apparatus for applying labels to bottles is shown in US 2004/0123955 A1 and to containers in U.S. Pat. No. 6,796,352 B1.